Помогите упростить

(m+4) ^2 - (m-3) (m+3)

(n+5) ^2 - n (n-7)

(6-n) (n+6) + (n-4) ^2

(m+n) (m-n) (m^2-n^2) + 2m^2 n^2

(a+3) (a-3) (a-3) (a+3) + 18a^2

^ - степень

(m+4) ^2 - (m-3) (m+3) = m^2+8m+16 - (m^2 - 9) = m^2 + 8m+16-m^2+9=8m+25

(n+5) ^2 - n (n-7) = n^2+10n+25-n^2 + 7n=17n+25

(6-n) (n+6) + (n-4) ^2=6n+36-n^2 - 6n+n^2 - 8n+16=52-8n

(m+n) (m-n) (m^2-n^2) + 2m^2 n^2 = (m^2 - n^2) * (m^2-n^2) + 2m^2 n^2 = (m^2 - n^2) ^2 + 2m^2 n^2=m^4 - 2m^2 n^2 + n^4 + 2m^2 n^2=m^4 + n^4

(a+3) (a-3) (a-3) (a+3) + 18a^2 = (a+3) ^2 * (a-3) ^2 + 18a^2 = ((a+3) * (a*3)) ^2 + 18a^2 = (a^2 - 9) ^2 + 18a^2=a^4 - 18a^2 + 81+18a^2=a^4 + 81